Internal-combustion engine.



G. C. DAVISON & J. W. ANDERSON. INTERNAL COMBUSTION ENGINE.

' V APPLICATION FILED FEB; 9, law 1,180,636. Patented Apr. 25,1916.

3 SHEE TSSHEET I- A TTORIVEYS e. C. DAVISON & J. w. ANDERSGN.

INTERNAL COMBUSTION ENGINE.

"APPLICATION FILED FEB-5,1315.

Patented Apr. 25, 1916.

3- SHEETS-SHEET 2- WIT/VEiSSES 7Z ZNVEYT Id i ,v

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ATTORNEY G. C. DAVISON & J. W. ANDERSON.

INTERNAL COMBUSTION ENGINE. APPLICATION FILED- FEB. 9, I915.

Patented Apr. 25,1916. 3 SHEETS-SHEET 3 [A M I of operation mg the engine in operation in either direcgearing being such medium, which air is ders of the engine and acts on the pistons UNITED s'rATns PATENT OFFICE.

GREGORY 0-. DAVISON AND JOHN W; ANDERSON, OF NEW LONDON, CONNECTICUT, ASSIGNCRS T0 ELECTRIC BOAT COMBANY, OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY.

To all whom it may concern:

Be it known that we, GREGORY C. DAVISON and JOHN W. An nnason, citizens of the United States, residing at New London, in

the county of New London and State of This invention relates-to internal combus tion engines and more particular-l &-.to mechanism foreiiectlng reversal oi th hrection of such an engine and for starttion.

The invention involves the provision of a simple form. of reversing gearing by which certain of the operating mechanism of the engine may be shifted to adapt the engine for rotation in the opposite direction, this that the changed relation of the operating mechanism may be established before the-engine is started in.

rotation in the reverse direction. 4

Another feature of the invention involves the provisionot' pneumatically operated dc vices for effecting the change in the relation of the operating mechanism incident to changing the direction of'rotation of the engine.

The invention also involves the provision of certain locking devices whereby, when the parts of the operating mechanism are set in the positions for rotation of the englue in the desired direction, they will be locked in that position and positively held against accidental 3 displacement. These locking devices are so constructed that they are automatically unlocked Without requiring additional manipulation on the part of the operator when effecting the necessary change in the relation of the operating mechanism incident tore'versing the'direction of rotation oi the engine.

The invention also involves the provision of an improved form of starting mechanism employing compressed "air as the starting admitted to the cylintherein. This starting mechanism is combined with the mechanism for reversing the Specification of Letters Patent.

tion, broken away .on lines 6--6 and 7-7 of Fig. 5,

PatentedApr. 25, 1916.

Application filed February 9, 1915. Serial No. 6,986.

engine so that the manipulation of a single valve inthe conduit leading from the compressed'a1r supply results in establishing the relation of the operating mechanism incldent to rotation in the desired direction andthen, without further manipulation, admits air or effects the admission of air to the cylinders for starting the engine.

These and other features of the invention will be better understood by reference to the followir -(h .?ription taken in connection with the accompanying drawings, which show the preferred embodiment of the invention. In these drawings, Figure 1 is an elevaand sectioned in part, of one end of the engine, Fig. 2 is a sectional elevation on. an enlarged scale showing the air cylinder and parts associated therewith,

Figs. 3 and 4 are horizontal sectional views on lines 3-3 and 4 4 ofFig. 2, Fig. 5 is a sectional elevation of the shiftable casing by which changes are eliected in the angular relation of the cam shaft to the engine shaft, Figs. 6 and 7 are horizontal sectional views andFig. 8

is an elevation, partially diagrammatic, of a portion of an internal combustion engine constructed in accordance with the invention.

Referring to these drawings, an engine is shown having a plurality of cylinders 9 which are mounted in the usual manner upon a casing 10 inclosing the crank-shaft 11 and the connecting rods which connect the crank-shaft with eral cylinders. may be provided for admitting fuel to the cylinders. in con ection with Diesel engines in which the fuel is admitted to the cylinders in liquid form.

The admission of the pistons' in the sev the fuel to the cylinders Any suitable mechanism The invention is of special utility and the admission of compressed air to the 1 cylinders when starting the engine is effectedi by air under the control of a cam shaft 12,

which is shown as extending along the 'upper ends of the cylinders and journale d in bearings formed therein. This'cam shaft'is driven by the crank-shaft 11 at a speed bearing a definite relation to the speed of the shaft 11. For this purpose the shafts llland 12 are provided withgears spectively, meshing with coacting gears 15 13 and 14:, re-' and 16. respectively, on a vertically disposed connecting shaft. This shaft is shown as; formed of two part-s l7 and 1,8 mounted for rotation in snitable bearings and in axial alinement. The two parts,17 and 18 of this shaft are connected together in a definite relation for operation of the engine in one direction and when reversal of the engine is to be effected. the two parts i? andtlfl' of the connecting shaft are shifted angularly, one relative to the other. so that the angular relation of the cam shaft 12 to the crank-shaft 11 is changed to a predeter mined extent. In this'way. the cams on the shaft 12 are turned through a definite angle unaccompanied by turning movement of the ;-ranl\'-sha1"t so as to establish them in the new relation required for operation of the engine in the opposite direction. This angular shifting of the relation of the parts 17 and 18 of the connecting shaft is effected by axial i novement of the means employed for connecting the parts 17 and 18, this means having spirally arranged groovesassociated therewith so that its axial move ment results in turning the part 18 of the connecting shaft and hence thecam shaft 1; through the desired angle. since the crankshaft 11 and the part I? of the connecting shaft geared thereto are held against turning. Secured on the shaft IT at the upper end thereof. is a collar 19 (Fig. 5) having a plurality of spirally arranged grooves in the outer surface thereof. These grooves receive shoes 20 which are secured by means of pins 21 upon the interior wall of a casing '22 which incloses the collar L). This casing .22 is also connected to the lower end of the shaft 13. this connection being a spline as shown at 23. so that. though the casing :22 may move vertically with relation to shaft 18. the casing 22 and shaft 18 always rotate together. The portion of the asing 2:2 inclosing the lower end of shaft in is provided with a circumferential groove adapted to receive a two-part ring 24 pivoted to an oper ating lever 25 whereby the casing 22 is moved vertically; It will be seen that when the shaft 17 is held against rotation by the crank-shaft and the casing :32 is moved vertically. the shaft 18 and the cam shaft con nected thereto will be turned in their bearings an amount depending upon the extent of movement of casing :22 and the pitch of the. spirally arranged grooves-iii the collar 1!). The turning, movement of the shaft 18 and the cam shaft effected in this way, is such that the cams on the canrshaft will be shifted the anuiunt necessary to effect reversal of the direction of rotation of the era glue The operating lever 25 is 'pivotally mounted intermediate its ends upon the wer end of a link 20. whose upper end is 1 voted upon the casing of the engine. The

end of lever 25 opposite to that connected to casing 22 is connected by means of a link 27 to the lower end of the rod 28 of a piston knitted in an air cylinder. This rod :28 is extended upwardly through the air cylinder and carries the piston of a dash-pot whereby the movements of the casingflfl are controlled and too rapid or irregular movement thereof preventet The construction of the referred to and the parts associated therewith, is shown in detail in Figs. 2, 3. and i. The air cylinder is shown at 29. At its ends it is provided with stalling-boxes through which the rod .28 extends. The dash-pot is shown at 30 having stalling-boxes at its ends through which rod extends and having r piston 31 secured on rod 28 and reciprocating within the cylinder of the dash-pot. The cylinder 29 is provided with a piston 32 secured on the rod 28.

The lever 25 is extended a short distance beyond the point of connection to the link 27 and its extreme end is connected by a link $3 (Fig. 1) to a to" 4. This slide is received in a vertically disposed guide-way provided for its reception in the casting of the cylinder 29 and it .is held in position in the guide-way by a cover-plate 35 which is secured to the casting l. The slide 34 is engaged by one or the other of two locking pins 36 and 37, the latter of which is shown in detail in Fig. 3 llachgof these locking pins has a piston 38 secured thereon or formed integral therewith and adapted to reciprocate horizontally in a small cylinder formed in the casting for the air cylinder 25). Also, each of these small"cylinders is closed at one end by a threaded plug 35) shaped to receive a spring 40 by which the piston 38 and the locking pin secured thereto are pressed in a direction to carry the end of the locking pin into a coacting opening in the slide 3- A port 41 leads into the cylinder for the piston which carries the locking pin 37 at the end of that cylinder adjacent to the slide 34; a similar port leads to the corresponding end of the upper cylinder for the piston which carries the Locking pin 36. From each of these cylinders, a port 42 leads to the cylinder in which the piston 32 reciprocates, this port {2 entering the cylinder for the piston 32 at the adjacent end of the cylinder, as shown in Fig. 2. It will be seen that when air under pressure is admitted through port til, it acts upon the piston 38 so as to move. it against the tension of spring 40 until the corresponding locking pin is withdrawn from the opening in slide 34 and after the .ocking pin has been so withdrawn from its locking relation to slide 34, the piston 38 opens the port 42 so that the airadi'nitted to the port 41 may pass through the port f2 and into the cvhnder 29 to act of! the pist n air cylinder just 32 therein and reciprocate the latter, The

reciprocation of piston 32 effects rockingv movement of the lever 25 and shifts thecasing 22 and this rocking movement of lever 25 causes the slide 34 to move vertically. After the vertical movement of the slide 34 has begun, the locking pin which was withdrawn cannot again come into its locking I position with respect to the slide, for even if the spring 40 be permitted to move the piston 38 and the locking pin, the latter will engage the side of the slide 34 andbe arrested thereby. When the movementof the piston 32 and slide 34 have been completed, the other locking pin will he moved by its spring 40 to project its end into the corre sponding opening-in the slide 34 so as to hold the slide .agalnst movement -unt1l air is admitted to the cylinder of that looking pin to withdraw it as above described.

In the wall, of the cylinder 29 are two ports 43 and 44 which are controlled by the piston These ports are so located that they are closed until the piston nears the end of itsinovement in one direction or the other. .Just asthe piston approaches the limit of its movement in one direction, it opens one of the two ports so that air may pass through the cylinder and out through that port.

Fig; 8 shows the air connections diagrammatically. A conduit leading from a source of supply of compressed air-is shown at 45 and this conduit is connected toa valve 46 from \vhichpipes 47 and 48 lead to the ports 41 of the upper and lower locking pins 86 and 37, respectively. 'The valve 46 is provided with an exhaust port 49 and is so constructed that either of the two pipes 47 and 48 may be connected to the supply pipe 45 and the other to the atmosphere at 49; y

The ports 43 and 44 leading from the air cylinder are connected together and to the devices for admitting starting air to the cylinders 9 of the engine by means of conduits 50. The valves by which the starting air is admitted to the cylinders 9 may be arranged to be actuated mechanically by cams on the cam shaft 12, or if desired these valves may he pneumatically actuated. In the construction illustrated in the drawings, the

air-inlet valves 51 on the several cylinders 9 are shown as adapted to be actuated mechanically by cams on the cam shaft and rho conduit. 50 is therefore shown as extending from the cvlinder 25) to all of the airinlet valves 51. If desired. the several airinlet .valves 51 may he pneumatically actuatcd and inthat case the air flowing from the cylinder 29 to the valves 51 would he merely the actuating air. the air admitted to the cyliiulcrs 5) being led-to the valves 51 by another conduit. In this latter case. a suitable distributor driven by' the engine shaft would he provided for controlling the supply of the actuating air .from the cylinder 29 to the several pneumatically actuated valves 51 successively in the desired order and at the proper time intervals.

The operation of the mechanism constructed as above set forth will now be described Iiigs. 2, 3 and 4 show the partsin the positions which they occupy when the engine is set for running in a given direction. The

lower locking pin 37 has been moved by its.

spring 40 to the operative position in which the end of the pin lies in an opening in the slide 34 so that the slide, the piston 32, the lever 25 and the casing 22, are all positively locked against unintended movement thereof. The upper locking pin 36 is in a slightly retracted position with its end in contact with the side ofthe 'slide34, the hole in the slide for the reception of the end of pin 36 being below the pin. If the engine were at rest, the handle of the valve 46 would be in a neutral position. To startthe enginein the direction for which the parts thereof had already beenset, the handle of the valve 46 would be turned to the position for admit-' ting air from the conduit 45 to the pipe 47 and to the port 41 of the upper locking pin 36. From that port the air would flow to the port 42, moving the piston 38 back a short distance if necessary, and this air passing through port 42 would flow through the cylinder 29, port 43 and conduit 50 into that one of the several cylinders whose piston was in the appropriate position. The air flowing to the cylinders thus would be admitted to the cylinders in theproper sequence by means ,of the cams controlling the several air-inlet valves and the starting of the oper- V ation of the engine would thus be effected. \Vhen the engine-began to operate under its own power, the handle of the valve 46 would be turned to the neutral position.

If it were desired to operate in the oppo-' upon the piston 32-so as to force the latter upwardly in the cylinder 29. This upward movement of the piston 32 would take place immediately after the slide 34 had been unlocked bythe retraction of pin 37 and would result in rocking the lever 25 so as toxhift From this life the casing 22. This movement of the casing 22 would turn the shaft. 1841s above described so as to effect the requisite turning movement of the cam shaft 12. At fh 'completion of the lmwardmovement of the p ston 32 that it in operation until it began to operate under its own power. Also, the upward movement of the plston 32 within the cylinder .29

would be accompanied by upward movement of the slide ill and when these parts reached the end of their upward movement, the upper locking pin 36 would be moved outwardly by its spring 40 to carry the end of the pin into its opening in the slide 3-l so that the slide and the other parts of the reversing gearing would be again locked so that they could notbe moved until air was admitted to the cylinder of the upper locle ing pin to effect the withdrawal of that pin.

It will thus be seen that the parts employed 1n reversing the direction of operation of the engine are positively locked against movement at all times except when they are intentionally unlocked for the purpose of eifecting the reversal. Furthermore, this locking mechanism, the mechanism for reversing the engine and the mechanism for starting the engine are all controlled from a single point and preferably by means of a single valve. The opening of this valve first effects the withdrawal of the pin 36 or 37 which at that time is serving to lock the mechanism, then moves the parts of the reversing mechanism to the reverse po sition and then, without further manipulation, admits air to the cylinders of the engine so as to start the engine in operation. The air cannot enter the cylinder 29 to move the piston 32 and shift the casing until after the locking pin hasbeen withdrawn from its locking position; also, the air ad mitted to cylinder 29 cannot flow from that cylinder to the inlet valves of the engine until after the piston and the casing 22 have completed their movement. This latter insures that the parts of the reversing mechanism will have completed their movement of reversal before the operation of the engine has begun by the air employed in starting. In this way certain defects of operation are avoided which result from starting the engine in operation slightly in advance of completing the movement of the parts employed for reversing the direction of the operation of the engine. Furthermore, when the movement ofthe parts employed in reversing the direction of operation of the engine has been completed, those parts are automatically and positively locked and thereafter are held against unintended movement.

An important feature of the construction struction but that the same may be varied in numerous respects without departing from the invention. The casing 22 and the spiral grooves with which it coacts are shown as located at the point where the shaft connecting the engine shaft andcam shaft is divided. If desired, however, these parts may be located at a different point in the connection from the engine shaft, to the cam shaft, as for instance, at the connectior of one of the gears employed to its shaft. Also, any desired form of connection of the air cylinder to the casing 22 may he employed other than the simple form ofpivoted lever 25 herein shown. In some" typet of engines a plurality of cam shafts are employed instead of one as in the engine illus trated, and in such case the air cylinder may be arranged to shift all of the cam shafts by means of suitable gearing, the several cam shafts being shifted through the same or different angles as may be required by the functions which they are to serve.

'hat we claim is:

1. The combination of an internal combustion engine including air-starting means therefor, a reversing control for the engine, and an air-supply line for supplying compressed air to operate both the reversing control and the air-starting means. said reversing control and said air-starting means being connected in the air-supply line in series; substantially as described.

:2. The combination of an internal combustion engine including an air starting means therefor, a reversing control for the engine, and a single means for operating the reversing control and for operating the air starting means after the reversing control has completed its movement of revcrsahsaid single means including an air-line within which are interposed in series said reversing control and said air-starting means; substantially as described.

3. The combination of an internal combustion engine including an lLl1-Sl fl1'l lI1g valve, a normally closed air-line for said valve, a reversing control for the engine, and a single pneumatically operated piston moving when actuated to operate the re-. versing control and to open said line;- substantially as described.

4. The combination or an internal combustion engine including an air-starting ion valve, a normally closed air-line for said valve, a reversing control for the engine, and

air-line normally out of communication with a single pneumatically operated piston in terposed in said. hue and moving when actuated first to operate the reversing control and after said reversing control has com-' pleted its movement of reversal to open said line; substantially as described.

' 5. The combination of an internal combustion engine, air-starting means therefor,

a reversing controlfor the engine, means for actuating the reversing control, and a normally closed air-line opened directly by the actuation of the said means to feed actuating airto the air-starting means; substantially as described. h

6. The combination of an internal conibustion engine including air-starting means thereforhaving valves and valve-controllers, a reversing means for the engine, a pneumatically actuated control for operating the reversing means, an air-line normally out of communication with the alr-starting means,

.' and a normally inoperative means which is rendered. operative by the movement of said pneumatically. actuated control to place said air-line in communication with the air-starting means and make the lattcr operative in response to the operation of the valve-controllers after the reversing means has been actuated; substantially as described.

7. The combination of an internal com bustion engine, a reversing control therefor,

aplurality of separate locking devices one of which engages withth'e reversing control in each of two positions of the latter, and means for pneumatically operating the engaging locking device to; release the reversing control and for then pneumatically operating the reversing control; substantially as described. 7

8. The combination of an internal combustion engine, a reversing means therefor including a pneumatically operated control, a, bolt for locking. the control, a

. pneumatically operated device for displaci. ing' the bolt to release the control, and a normally. ineffective 'air-line' for operating -the control which air-line is re ,dered effective by the movement of said device; suljstan tially as described. i

9. The combination of an internal combustion engine, a reversing control therefor, a'plurality of separate locking devices for the reversing control one of which engages with the reversing control in each of two positions of the latter, and a single means for operating the engaging locking device to release the reversing control and then to operate the reversing control, the other looking device being actuated automatically to engage the reversing control after the lat ter has been operated; substantially as described.-

10. The combination of an internal combustion engine including air-starting means therefor, a reversing control therefor, an

the air-starting means, 'a plurality of separate locking devices for the reversing control one of which engages with the reversing control in each of two positions of the latter, a single means for operating the engag- I ing locking device to release the reversing control, the other locking device being actuated automatically to engage the reversing control after the latter has been operated, and means for opening said air-line to operate said a'ir-starting means controlled by the movement of the reversing control; subtrol, and an air-line normally ineffective to operate either the control or the air-starting means, said air-line being by the operation of said device rendered effective to operate said control and said air-line being by the operation of said control rendered effective to supply air to said air-starting means;

substantially as described.

12. The combination of an internal combustion engine, an airstarting means there for, a reversing control for the engine, a plurality of locking devices for the reversing control, an air supply line having interposed therein in series one of said locking devices,

. saidreversing control and the valves of'said air-starting means, and a single means forv operating the locking device last mentioned to release the reversing control and render said line eflective to operate the reversing control, for then operating'the reversing control and'rendering said line effective to feed air to the air-starting means, and for then feeding air through said line: to said air-starting means; substantially as described. i i 13 The combination of an internal combustion engine, an air-starting means therefor, a reversing control for the engine including a pneumatically operated piston, locking means for the reversing control in eluding a pneumatically operated piston, and an-air-supply line having interposed therein in series the first mentioned piston,

' the second mentioned piston and said airstartinig anda connection from said cylinder to the cylinders of the engine for conveying air to the cylinders of the engine to start the eni g-ine when time reversed: substantially as described.

15. An internal combustion engine having the combination of a crank shaft, a cam shaft, :1 divided connecting shaft geared to said shafts. a member connecting the two parts of said divided shaft to cause simultaneous rotation thereof, said member being movable in the direction of the length of the divided shaft and connected to one of the parts thereof by spiral threads, and pneumatically actuated devices for reciprocating said member; substantially as described.

16. The combination of an internal combustion engine.a reversing means therefor including a piston movable to reverse the engine, a cylinder within which said piston is located. a hich'ing belt, a second piston controlling the position of-the locking bolt, a cylinder within which the second piston, is located, a member movable with the reversing means and engaged by said bolt when the reversing means is in one of the running positions, an air-line leading from a source of supply to the second pistons cylinder to supply air thereto for displacing the second piston to disengage the bolt from said Incinher, and an air-passage leading fronrthe second piston s cylinder to the first pistons cylinder which air-passage is opened by the movement of the piston in the second cylinder to actuate said locking bolt; substantially as described.

17. The combination oi an internal combustion engine. a reversing means therefor including a piston movable to rcversethe eugine. a cylinder within which said piston is located. a locking bolt. a second piston eontrolliug the position of the locking bolt, a cylinderwithin which thesecond piston is located. a member movable with the rovers ing means and engaged by said bolt when the reversing means is in one of the running positions. an air-line leading from a source of supply to the second pislons cylinder to supply air thereto for displacing the second piston to disengage the bolt from said member. an air-passage leading from the second pistous cylinder to the lirst pistons cylindei'.\\'hich air-passage isopencd by the movement of the piston in the second cylinder to actuate said locking bolt. and an air connection from the lirst cylinder to the ail-startlug valves of the engine; substani inllv as described.

W. The conibiimtion of an internal coin busliou engine, a reversing means therefor ncludiog a piston movable to reverse the engine. a cylinder within which said piston is a locking bolt, a second piston conlocated, trolling the position of the locking bolt, a cylinder within which the second piston is located, a. member movable with the reversing means and engaged by said bolt when bastion engine,

the reversing means is in one of its running positions, an air-line leading from a source ofsupply to the secohd pistons cylinder to supply air thereto f r displacing the second piston to disengage he bolt from said member, an air-passagegiearliug from the second pistons cylinder the first pistons cylinder which air-passage fis opened by the movement of the piston/in the second cy1inder to actuate saiddoclcin bolt, and a con; nection leading to the ,ainstarting valves of the engine having its coinnmnication with said air-line controlled by the movement of the piston in the first cylinder; substantially as described.

19. The combinatioiiitof an internal combustion engine, a cylilfder, a piston reciprocating therein, a reversing means operated by the piston to set the valve-controllers of the engine for running ih one direction when the piston is at one end of said cylinder and to set said valve-controllers for running in the reverse direction when the piston is at the other end of said cylinder, a connection leading from a source of air supply into the upper part of the cylinder, a connection leading from said source into the lower part of the cylinder, a connection leading tron. the upper part of the cylinder to the airstartlng means of the engine, and a connection leading from the lower part of the cylinder to said air-starting means, one of the two last mentioned connections being closed and the other opened latter is at either end of its range of movement within the cylinder; substantially as described. l

20. The combination of an internal com a cylinder, a' piston reciprocating therein, a reversing means operated by'the piston to set the valve controllers of the engine for running in one direction when the piston is at one end of said cylinder and to set said valve controllers for running in the reverse direction when the piston is at the other end of said cylinder, a connection lead ing from a source of air supply into the up per part of the cylinder, a connection leading from said source into the lower part of the cylinder. a connection leading from the upper part of the cylinder to the air-starting means of the engine, and a connection leading from the lower part of the cylinder to said airby the piston when the piston during the major part of the latters travel from one end of the cylinder to the other; substantially asclescribed.

21. In an internal combustion engine, the combination of the cylinders, air valves thereon for starting, a cain shaft having cams thereon for actuating certain of the valves of the engine. means for shifting said cams to adapt the engine for operation in one dlrection or the other, a cylinder and.

ineans is movable to one or the other ot'two operative positions. air-starting valves on the cylinders. and means tor supplying compressed air to SilltliYtllVGS which means 15' effective ivhen said shifting means is in one or the other of its operative. positions but not when it is in an intermediate position; Substantially as described.

23. In an internal rombustion engine. the

coinbinatimi oi the cylinders, a cam shaft havin; cams thereon for actuating certain of the valvesot' the engine, means for shitting said cams to adapt the engine for operation in one direction or the other. a lock for said shi l ting means. air-starting: valves on the cylinders, a source of supply of compressed air :l'or said valves, and a single In an internal combustion engine, the

means for first operating said lock, then operatingsaid shitting means and then connecting thesouree of supply of compressed air tothe air-starting valves; substantially as described. v

2%. In an internal combustion engine, the combination of the cylinders, a cam shaft having cams thereon for actuating certain of the valves of the engine, means for shifting said cams to adapt the engine for operation in one direction or the other, a lock for said shifting means, and a single means't'or first operating said lock to release said shifting means and then operating the shifting means to adapt the engine for operation in the opposite direction; substantially.- as described.

In an internal combustion engine, the combination of the cylinders, a cam shaft having'cams thereon t'or actuating certain of the valves of'the engine. means for shifting said cams to adapt the enginefor operation in one direction or the other, locking mechanism for said shifting means, and a single means for operating thelocking mech-' anism to release the shifting means and then operating the shifting means to effect re- "versal. of the engine, said locking mechanism being operated automati ally after the shifting means has been actuated to again lock the shitting means, substantially as described.

In testimony whereof \ve aflix our'signatures,.inIpi-esence of two witnesses.

GREGORY C. DAVISON. JOHN \V. ANDERSON. \Vitnesses F. YV. BLAKE, E. C. Hnxennrono. 

